The research is to study (1) the enzymatic and nonenzymatic reactions of glyoxylate, a highly reactive aldehyde, and (2) the enzymatic dehalogenation of chlorofluorohydrocarbons to glyoxylate and other derivatives. The enzymatic work with glyoxylate is concerned mainly with its reduction and oxidation to glycolate and oxalate, respectively. These reactions are catalyzed in mammalian systems by lactate dehydrogenases, utilizing diphosphopyridine nucleotide as the coenzyme. The nonenzymatic reactions of glyoxylate under study simulate the enzymatic reactions Gyloxylate teacts with diphosphopyridine nucleotide analogs in the presence of an amino compound to yield stable condensation products. The mechanism of formation and the structures of the products are currently under investigation. Enzymatic catabolism of the anesthetic methoxyflurane is investigated to see whether glyoxylate is an intermediate on the pathway to the end product, oxalate. A glutathione-dependent enzyme, capable of catalyzing dehalogenation of methoxyflurane, has been identified in liver extracts. This enzymatic system is independent of the microsomal mixed function oxidases and may be a general system for catalyzing dehalogenation of other chlorofluorohydrocarbons. BIBLIOGRAPHIC REFERENCES: W.A. Warren, F.D. Baker, and J. Bellantoni. Enzymatic defluorination of methoxyflurane. Biochemical Pharmacology, 25, in press (1976).